Significant Structures of the Knee Joint Flashcards
What are the two joints that make up the knee?
tibiofemoral, patellofemoral
What type of joint is the knee joint?
Hinge
Why is the knee hinge joint more complex than the elbow hinge joint?
rounded condyles roll across the superior surface of the tibia (points of contact are constantly changing), some degree of rotation is permitted
patellar ligament
patella embedded within the patellar ligament, anterior surface of joint, provides support to anterior surface of knee where there is no continuous capsule
tibial collateral ligament (MCL) attachment
medial reinforcement, from the lateral epicondyle of the femur to the head of the fibula
fibular collateral (LCL) attachment
lateral reinforcement, from the medial epicondyle of the femur to the medial surface of the medial condyle of the tibia
What do the MCL and LCL have in common during full extension?
tighten only at full extension where they stabilize the joint
arcuate popliteal ligament
posterior aspect of the head of fibula, fibers pass superiomedially over tendon of popliteus then blend with articular capsule of knee
restrains excessive tibial rotation
oblique popliteal ligament
extends across the back of knee from medial condyle of the tibia to the lateral condyle of the femur, blends with central, posterior part of the fibrous later of the articular capsule of the knee
anterior cruciate ligament (ACL) attachment
from anterior aspect of the intercondylar eminence of the tibia with the medial surface of the lateral femoral condyle
posterior cruciate ligament attachment
from the posterior aspect of the intercondylar eminence of the tibia to the lateral surface of the medial femoral condyle
ACL Function
limits anterior movement of the tibia relative to the emir in all positions of joint movement
PCL Function
limits posterior movement of the tibia relative to the femur in all positions of joint movement
What happens to the MCL in a clipping type injury (knee abduction)
ligament tears with meniscus because of its attachment to the medial meniscus
posterior meniscofemoral ligament attachment
from the posterior part of the lateral meniscus to the lateral surface of the medial femoral condyle
Function of posterior meniscofemoral ligament
supports PCL in reducing posterior displacement of tibia on femur - controls the motion of the lateral meniscus in conjunction with the tendon of popliteus muscle during flexion
What nerve does the patella tendon reflex test for?
L4
Why injury is the medial meniscus (semilunar cartilage) more susceptible too? Why?
because of its attachment to the MCL, it is more likely injured from displacement or twisting injuries
What are the two intercondylar attachements between the tibia and femur?
the cruciate ligaments (ACL/PCL)
What are the two main voluntary motions of the knee?
flexion and extension
What are the minor motions of the knee?
anterior/posterior, medial/lateral glides, anteriomedial/posteriomedial
Postero-lateral glide dysfunction
extension of the knee, lateral condyle reaches physiologic limit and articular surface of medial condyle of femur continues to track on tibial plateau causing internal rotation of tibia - posterior and lateral glide of the tibial plateau in full extension
antero-lateral glide dysfunction
happens in full flexion, lateral condyle of femur finds barrier sooner therefore the medial condyle continues to roll over tibial plateau which causes tibia to rotate externally - glide tibial plateau anteriorly and medially
Gastrocnemius Origin
Femur; medial head: above the medial femoral condyle
Lateral head: above the lateral femoral condyle
Gastrocnemius Insertion
dorsum of the calcaneus (achilles tendon)
Gastrocnemius Action
Flexes leg; plantar flexes the foot
Popliteus Origin
lateral condyle of the femur
Popliteus Insertion
posterior surface of the tibia above soleal line
Popliteus Action
flexes and rotates leg medially (with foot planted, it rotates the thigh laterally)
Plantaris Origin
above the lateral femoral condyle (above the lateral head of gastrocnemius)
Plantaris Insertion
dorsum of the calcaneus medial to the calcaneal tendon
Plantaris Action
flexes leg, plantar flexes the foot
Semimembranosus Origin
upper, outer surface of the ischial tuberosity
Semimembranosus Insertion
Medial Condyle of tibia
Semimembranosus Action
extends thigh, flexes leg
How would you push the fibular head to test the glide of the joint
Posteromedially and anterolaterally
